The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Mismatches of devices due to uncertainties in the manufacturing process as well as changes of supply voltage or temperature can introduce an offset voltage that reduces the performance of a system or integrated circuits. Dynamic offset cancellation techniques, such as chopping, have been developed to reduce the offset voltage during the operation of a system or integrated circuits. Chopping is a frequency modulation technique in which the signal and offset are modulated to different frequencies, and the offset can be filtered out thereafter using a filter. However, implementation of a filter may increase the output resistance of the system or circuits, which can cause difficulty for maintaining voltage accuracy in a voltage reference circuit.